Originally Posted by Gayle
Minions of Satan doesn't have a very 1920's feel to the phrase.
Whatever Hoover's personal opinions were, he tended to use more legalese and moralist rhetoric rather than satanic overtones.
It was McPherson who was said to have used the 'minions of Satan' phrase, and it really has more of a post-Revival feel to me, the sort of thing that would come from a people that started naming their kids Zechariah and Isaiah because they were Biblical names. I am not aware actually of Herbert Hoover having a tendency to use legalese, since he was a businessman originally.
However, the OP says Hoover was known as the Radio Czar - my impression was that the 'czar' usage came in with either Carter or Reagan. It sounds very un-1920s or 1930s, especially since the Russian monarchy had recently been overthrown and this was generally recognized as a good thing, and the negatives of the Soviet regime had not yet come to light, so referring to the type of person they overthrew would not be seen as a positive. Of course, the usage may have been intended as an accusation of overbearing and possible extralegal exercise of authority, rather than the intended usage over the past few decades of someone who has broad authority to make different agencies respond on the issue.